Abstract: A fiber optic communications link having PMD characterization across multiple optical channels to identify PMD problems. The communications link has adaptive PMD controls employed along the optical link, whereby PMD phenomena detected by instruments, such as PMD compensators, are interpreted as being either attributable to perturbation of fiber characteristics at large, or by failure of PMD equipment along the link. The present invention avoids taking unnecessary control or maintenance actions upon PMD related controllers and compensators. PMD notifications from various PMD compensators are correlated to identify which portion of the link has undergone a change in polarization characteristics to further identify PMD related errors and problems.

Abstract: A method and apparatus for managing state-of-polarization (SOP) controllers along an optical communications link. When the polarization-mode dispersion (PMD) in the link exceeds a preset limit as determined by a PMD compensator, the SOP controller is directed to change rotation angle in an arbitrary fashion. This shift is only undertaken after other indicators are examined to determine that PMD is the main problem affecting the link, and not simply a consequence of a separate problem that the SOP controller rotation angle should not try to fix. By reducing unnecessary SOP adjustments which can disrupt data traffic, the reliability of the optical link is improved.

Abstract: A fiber optic communications link having PMD characterization across multiple optical channels to identify PMD problems. The communications link has adaptive PMD controls employed along the optical link, whereby PMD phenomena detected by instruments, such as PMD compensators, are interpreted as being either attributable to perturbation of fiber characteristics at large, or by failure of PMD equipment along the link. The present invention avoids taking unnecessary control or maintenance actions upon PMD related controllers and compensators. PMD notifications from various PMD compensators are correlated to identify which portion of the link has undergone a change in polarization characteristics to further identify PMD related errors and problems.

Abstract: A method and apparatus for managing state-of-polarization (SOP) controllers along an optical communications link. When the polarization-mode dispersion (PMD) in the link exceeds a preset limit as determined by a PMD compensator, the SOP controller is directed to change rotation angle in an arbitrary fashion. This shift is only undertaken after other indicators are examined to determine that PMD is the main problem affecting the link, and not simply a consequence of a separate problem that the SOP controller rotation angle should not try to fix. By reducing unnecessary SOP adjustments which can disrupt data traffic, the reliability of the optical link is improved.

Abstract: A method and apparatus for managing state-of-polarization (SOP) controllers along an optical communications link. When the polarization-mode dispersion (PMD) in the link exceeds a preset limit as determined by a PMD compensator, the SOP controller is directed to change rotation angle in an arbitrary fashion. This shift is only undertaken after other indicators are examined to determine that PMD is the main problem affecting the link, and not simply a consequence of a separate problem that the SOP controller rotation angle should not try to fix. By reducing unnecessary SOP adjustments which can disrupt data traffic, the reliability of the optical link is improved.

Abstract: A fiber optic communications link having PMD characterization across multiple optical channels to identify PMD problems. The communications link has adaptive PMD controls employed along the optical link, whereby PMD phenomena detected by instruments, such as PMD compensators, are interpreted as being either attributable to perturbation of fiber characteristics at large, or by failure of PMD equipment along the link. The present invention avoids taking unnecessary control or maintenance actions upon PMD related controllers and compensators. PMD notifications from various PMD compensators are correlated to identify which portion of the link has undergone a change in polarization characteristics to further identify PMD related errors and problems.

Abstract: The present invention provides a method and apparatus for an improved chromatic dispersion compensator. In an apparatus aspect, the present invention includes a channel separator for separating a wavelength division multiplexed light comprising a plurality of channels, the plurality of channels containing undesired chromatic dispersion and dispersion slope; and a plurality of partial-channel-set dispersion compensation devices optically coupled to the channel separator in a cascade arrangement, wherein each partial-channel-set dispersion compensation device includes: a virtually imaged phased array (VIPA) optically coupled to the channel separator, and a light returning device optically coupled to the VIPA, wherein a combination of the VIPA and the light returning device compensates for the undesired chromatic dispersion and dispersion slope by propagating each wavelength of the plurality of channels along a different path length.

Abstract: Dense wavelength division multiplexing within a 1310 nm band is accomplished over a single mode fiber. Carrier wavelengths are selected from within two windows, a low subband and/or a high subband, on either side of a guardband. The guardband includes the zero dispersion wavelength .lambda..sub.0 of a single-mode fiber in the optical communication link and separates low subband and high subband within the 1310 nm band. Dispersion compensation is provided for carrier signals in each dense WDM channel in the low and high subbands.

Abstract: A system and method for optimizing the performance, in a multichannel optical transmission system, of an optical signal regenerator, by compensating for input signal power fluctuation and for output signal gain change, and by mildly filtering individual wavelengths between gain block stages. A system and method to provide amplification and refinement of a bidirectional optical signal in a single amplification and refinement stage.

Abstract: A system and method for optimizing the performance, in a multichannel optical transmission system, of an optical signal regenerator, by compensating for input signal power fluctuation and for output signal gain change, and by mildly filtering individual wavelengths between gain block stages. A system and method to provide amplification and refinement of a bidirectional optical signal in a single amplification and refinement stage.